My 2017 iMac running slow. Is it salvagable? (etrecheck report)

This is a massive issue no one has mentioned:

Hardware Information:

    iMac (21.5-inch, 2017)

        Status: Supported

    iMac Model: iMac18,1

    2.3 GHz Dual-Core Intel Core i5 (i5-7360U) CPU: 2-core

You have the crippled educational/institutional model iMac, created to appeal to bulk buyers with limited computing power needs.

It has a slow laptop-class 2-core processor. The standard consumer model that year, the iMac 21.4-inch 4k, had a proper desktop class 4-core processor whose minimum 3.0ghz version was 50% faster than yours for only an 18% increase is purchase cost.

⚠️ Spend NO money except for an external USB3 SSD boot volume. RAM will not help a failing hard drive, and the CPU is not upgradeable.

Add the fact that the computer was not designed to be opened by the end user means you need professional help to add RAM or replace the internal drive. Figure two hours labor at US$65-80/hour from NW US providers I have polled. That, and the required reseal kit, are in addition to the cost of components. And you will still have an under-performing laptop-class processor. Not worth it.

Due the difficulty and high chance of damage to that model, some Apple Authorized Service Providers won't even work on sealed-case iMacs like yours.

I see one "cleaning" app that you do not need:

User Login Items:

    [Not Loaded] TCLoginItemHelper (App Store - installed 2023-09-08)

        Modern Login Item

        /Applications/CleanerOne.app/Contents/Library/LoginItems/TCLoginItemHelper.app

Sometimes removing so-called cleaning apps (110% useless on any any Mac made after OS 10 was introduced in ~2000) may improve drive scores, but your drive cannot do faster than about 80MB/sec when healthy and on a good day. 80MB/sec is still miserable slow with modelr macOS versions.

The external boot volume will improve felt performance remarkably, and you can still use the external for extra storage for your next computer.

Would something like a "High-speed 30TB/16TB/8TB/4TB/2TB/1TB Portable SSD External Solid State Drive USB" in 1TB be enough?

Using an external SSD as the startup disk will dramatically increase performance. However, be careful in what SSD you choose. I've seen a significant increase in the amount of counterfeit SSD products listed on shopping sites. It would be safe to stick to the Apple Store and choose the LaCie 500GB Mobile SSD Secure USB-C Drive - Gray - Apple.

Here are setup instructions for using an external SSD as the iMac's startup disk: Use an external SSD as your startup disk … - Apple Community.

-Jack

First be aware that you purchased the slowest Mac that Apple offered at the time of purchase: 8 GB RAM and a 5400 rpm rotational hard drive.

Also you've installed some very unnecessary software: CleanerOne. There is no reason to ever install or run any 3rd party "cleaning", "optimizing", "speed-up", anti-virus, VPN or security apps on your Mac.  This documents describe what you need to know and do in order to protect your Mac: Effective defenses against malware and other threats - Apple Community and Recognize and avoid phishing messages, phony support calls, and other scams - Apple Support.  

There are no known viruses, i.e. self propagating, for Macs.  There are, however, adware and malware which require the user to install although unwittingly most of the time thru sneaky links, etc.   

Anti Virus developers try to group all types as viruses into their ad campaigns of fear.  They do a poor job of the detecting and isolating the adware and malware.  Since there are no viruses these apps use up a lot of system resources searching for what is non-existent and adversely affect system and app performance.

There is one app, Malwarebytes, which was developed by a long time contributor to these forums and a highly respected member of the computer security community, that is designed solely to seek out adware and known malware and remove it.  The free version is more than adequate for most users.  

So uninstall CleanerOne according to the developer's instructions.

As you've been made aware the drive's read and write speeds are abysmal. If budget is a concern you can improve the speeds by around 10x (write) and 15x (read) with this setup:

With a dedicated external case and SSD those speeds can be even higher. I recommend drives from OWC (MacSales.com) as they have proven reliability, excellent customer support and warranties. 

If you go for a cased SSD then for your model contact OWC's customer support and get their recommendation for the SSD model that would best suit your iMac model, work requirements and budget. 

I use the above setup with a 4 TB SSD for Time Machine.

Hello Jack_Hardman,

The report also states:

Failing hard drive - This computer has a hard drive that appears to be failing.

You will want to backup your data with Time Machine and consider replacing the internal drive with an SSD (your current disk is an HDD, i.e. a mechanical hard drive).

Your main drive is dismally slow:

Write speed: 23 MB/s

Read speed: 30 MB/s

My solution was to create a bootable external SSD on my 2015 model. That dramatically increased performance.

I didn't look at the rest of the report as you are only concerned about "slowness".

Increasing RAM will not increase speed. You may get a memory starved app to run better but that's not the system as a whole.

I used a 512GB Samsung T7 external drive. "Enough" is a bit vague. Enough for what? macOS can run efficiently on a 120GB drive just as well as it does on an 8TB drive. Regardless of available space, the OS is only going to take up so much on any drive.

The remainder of the drive will be used for 3rd party apps and data you create, copy or download. You have to decide how much is "enough" based on your work habits.